Locating device for temperature compensated parallax barrier supporting system

ABSTRACT

Cooperating means formed between a temperature compensating member having an expansion loop and a sidewall of a parallax barrier are provided to insure centering of the loop within a preformed opening in the barrier sidewall. The cooperating means comprise protruding portions and matching receiving openings therefor, either of which may be formed on either member with the mating portion formed on the other member.

Mnited States Patent Inventor Benedict F. Vitale Auburn, N-Y. Appl, No.91,388 Filed Nov. 20, 1970 Division of Ser. No. 786,183, Dec. 23, 1968Patented Aug. 17, I971 Assignee Sylvania Electric Products Inc.

LOCATING DEVICE FOR TEMPERATURE COMPENSATED PARALLAX BARRIER SUPPORTINGSYSTEM 3 Claims, 5 Drawing Figs.

U.S. Cl 313/85 S, 313/288, 313/292 Int. Cl ..H0lj 29/06,

HOlj 3/38 [50] Field of Search 313/85 S, 69 C, 70C, 92 PDF; 92 B [56]References Cited UNITED STATES PATENTS 3,330,980 7/1967 Shrader 313/853,524,096 8/1970 Kuryla et al. 313/85 Primary Examiner-Robert SegalAtt0rneys-Norman J. OMalley, Donald R. Castle and William H. McNeil]ABSTRACT: Cooperating means formed between a temperature compensatingmember having an expansion loop and a sidewall of a parallax barrier areprovided to insure centering of the loop within a preformed opening inthe barrier sidewall. The cooperating means comprise protruding portionsand matching receiving openings therefor, either of which may be formedon either member with the mating portion formed on the other member.

PATENIEUAucWmn 3,600,622

SHEET 10F 2 INVENTOR. BENEDICT F VITALE g. 3 BY fi ajl ATTORNEYPATENTEUAUGI'HHII 3,600,622

SHEET 2 OF 2 INVEN'I'OR. BENEDICT F. VITALE ATTORNEY CROSS-REFERENCE TORELATED APPLICATION BACKGROUND OF THE INVENTION This invention relatesto color cathode ray tubes and more particularly to temperaturecompensated, parallax barrier supporting systems for use therein.

'In conventional color cathode ray tubes in use today, the

light-emitting screen is comprised of a pattern of different coloredlight-emitting phosphors. Positioned behind the screen; i.e., betweenthe screen and the electron source which energizes the phosphors toluminescence, is a parallax barrier which aids in color selection. Thebarrier is releasably mounted by means of springs within the tube-and isprovided with a foraminated pattern which is in accurate registry withthe phosphor pattern on the screen. During operation of the tube thebarrier enlarges due to the heat generated therein by the impingement ofthe electron beams thereon. This increase in size has, in the past,caused some loss of registration in the tube resulting in an impropercolor balance. To counteract this effect, the supporting springs havebeen attached to the barrier sidewalls through the intermediary of abimetallic element or baseplate which is provided with an expansion loopor hinge. The bimetallic baseplate utilizes the heat generated in thebarrier to change the position of the barrier during operation of thetube in a controlled manner to substantially maintain the desiredregistration. For a more detailed operation of the bimetallic device,reference may be had to US. Pat. No. 3,330,980. The expansion loop onthis element, when-installed on a parallax barrier, projects inwardlytoward the center of the tube. To accommodate this projection a slot,larger in size than the loop, is provided in the barrier sidewall. Toinsure proper operation of the device, the loop must be centered withinthe opening to insure its nonbinding expansion and contraction. In thepast this has been a tedious and time consuming hand operationwith anoperator attempting to visually center the device and maintain it inposition while it was welded or otherwise permanently fixed in position.Besides the disadvantages named above, there was no particular guaranteeof success.

OBJECTS AND SUMMARY OF THE INVENTION.

It is, therefore, an object of the invention to enhance the operation ofcolor cathode ray tubes employing these devices.

It is another object of the invention to insure nonbinding operation ofthese devices.

It is yet another object of the invention to remove operator error as afactor in the installation of such devices.

Theseand other objects are accomplished in one aspect of the inventionby the provision within a color cathode ray tube of the class described,of cooperating baseplate locating means formed on the baseplate and thesidewall of the parallax barrier to achieve substantially centrallocation of an expansion loop within a preformed opening whereby itsnonbinding action during operation is insured.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic sectionalview of a typical color cathode ray tube;

FIG. 2 is a partial perspective view illustrating one embodiment of theinvention;

FIG. 3 is a partial perspective view illustrating another embodiment ofthe invention;

FIG. 4 is a partial perspective view illustrating yet another embodimentof the invention; and

FIG. 5 is a partial perspective view illustrating still anotherembodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS For a better understanding ofthe present invention, together with other and further objects,advantages and capabilities thereof, reference is made to the followingdisclosure and appended claims in connection with the above-describeddrawings.

Referring now to the drawings with greater particularity, there is shownin FIG. 1 a color cathode ray tube 10 having a faceplate 12 with apatterned phosphor screen 14 disposed on the interior surface thereof. Aperipheral sidewall 16 extends from faceplate l2 and joins asubstantially funnel-shaped body 18. The narrow end of the funnelterminates in a cylindrical neck 20 which encloses an electron source22, which is typically in the form of three electron guns. A parallaxbarrier 24 is releasably mounted within the tube adjacent the screen.The tube is evacuated as is conventional in the art and is provided withsuitable leads (not shown) for making electrical connection to theproper components.

The parallax barrier 24 comprises a relatively fragile apertured portion26 which is fixed at its peripheral edge to a relatively rigid frame 28.The frame provides the parallax barrier sidewalls 30 to which thesupporting springs are attached. The configuration of the apertures inportion 26 may be either substantially circular or rectangular dependingupon the screen pattern.

Referring now to FIG. 2 there is shown a section of parallax barrier 24together with one of its spring support systems 32. Normally, in currenttubes, either three or four such systems are utilized; however, sincethey are all substantially identical, only one is shown here. The springsupport system comprises a bimetallic baseplate 34 having upper andlower sections 36 and 38 respectively, joined together by an expansionloop 40 which projects from the plane of the baseplate inwardly towardthe center of the tube 10. To accommodate the loop 40 there is provideda substantially rectangular loop-receiving opening 42 formed in sidewall30.

A leaf spring 44 is attached to upper portion 36 of the baseplate 34 andprojects outwardly therefrom. The free end of spring 44 is provided withan aperture 46 for engaging a stud 48 which is provided on the interiorsurface of peripheral wall 16.

In order for the loop to function properly, opening 42 must be largeenough to provide for freedomof movement thereof during operation.Further, even when the opening is sufficiently large, care must be takento assure that the loop is properly centered therein and is not bindingagainst one of the edges of the opening.

To insure this desirable result, there is provided cooperating baseplatelocating means formed on the baseplate 34 and the sidewall 30. In theembodiment shown in FIG. 2 the locating means comprises a substantiallyelongated protrusion 50 extending from the plane of the baseplate 34toward the center of the tube. A matchingly configured second opening 52is formed in sidewall 30 to receive protrusion 50 with a substantiallysnug fit. The second opening 52 should be just enough larger thanprotrusion 50 to allow for easy entry thereinto without allowing anyroom for shop, since this would permit the baseplate 34 to bemisaligned. The actual amount of tolerance allowed between the secondopening 52 and the protrusion 50 will depend in part upon the materialsbeing utilized and the cost factor willing to be borne by the tubeproducer. ,7

An alternate embodiment of the locating means is shown in FIG. 3 whereinit comprises at least two protuberances 54 and 56 respectively which, inthis instance, are shown as being formed on barrier sidewall 30.Matching openings 58 and 60 are provided in baseplate 34. Obviously, theconditions may be reversed and the protuberances may be formed on thebaseplate with the openings in the sidewall. In the instant case theprotuberances are shown as being cylindrical; however, it is to beunderstood that this is illustrative only and that other configurationsmay be employed.

Another embodiment of the invention is illustrated in FIG. 4 wherein thelocating means comprises a single, substantially elongated protrusion 62extending outwardly from the plane of sidewall 30. A matching opening 64is provided in baseplate 34. The protrusion 62 may be punched from thesidewall 30 or it may be an additional member welded thereon.

A still further embodiment is shown in FIG. 5 wherein the locating meanscomprises an adjacent pair of edges of baseplate 34; for example, 66 and68 respectively. The complimentary locating means on the sidewall 30then takes the form of a substantially L-shaped bracket 70 having a leg72 and a leg 74. In this embodiment, fitting the edge 66 against leg 74and edge 68 against leg 72 will provide the desired alignment.

in each of the above-described embodiments, after the cooperativecoupling of the locating means, the baseplate is permanently affixed inposition on the sidewall 30 by means of welding or other suitablemethod.

Thus, it will be seen that there is provided by this invention novelmeans for enhancing the operation of color cathode ray tubes employingbimetallic, temperature-compensating devices. Nonbinding action of theexpansion loop is insured and the factor of operator error is removed.

While there have been shown and described what are at present consideredthe preferred embodiments of the invention, it will be obvious to thoseskilled in the art that various changes and modifications may be madetherein without departing from the scope of the invention as defined bythe appended claims.

I claim:

1. A color cathode ray tube having an envelope and a patterned, mosaicscreen therein; a parallax barrier mounted within said tube adjacentsaid screen comprised of a relatively fragile apertured portion and arelatively heavy frame having a wall, said apertured portion beingattached at its peripheral edge to said wall of said frame, each of theapertures in said barrier being aligned with particular areas of saidmosaic screen; said mounting for said barrier in said tube includingmeans for maintaining said alignment during tube operation, saidlast-named means comprising: a plurality of temperature compensatingmounting members spaced about said wall of said frame, each comprisinga.bimetallic baseplate formed from contiguous materials having differentthermal coefficients of expansion and being formed to have a protrudingextending loop extending therefrom, said loop being responsive totemperature changes within said tube and being formed between first andsecond ends of said baseplate; means for attaching a first end of eachof said baseplates to said wall of said frame; an opening formed in saidwall of said frame to receive said loop; cooperating baseplate locatingmeans formed on said first end of said baseplate and said wall toachieve substantially central location of said loop within said openingwhereby its nonbinding action is insured; said cooperating baseplatelocating means comprising a plurality of projections extending from theplane of said wall and a like number of openings in said baseplate, saidopenings being configured as said projections and providing a snug fitof said projections therein; a like plurality of spaced studs projectinginternally of said tube and attached to said envelope; and a likeplurality of leaf springs each having one end attached to one of saidstuds and the other end affixed to one of said second ends of one ofsaid baseplates.

2. The invention of claim 1 wherein said projections are two in number.

3. The invention of claim 1 wherein said projections are cylindrical.

1. A color cathode ray tube having an envelope and a patterned, mosaicscreen therein; a parallax barrier mounted within said tube adjacentsaid screen comprised of a relatively fragile apertured portion and arelatively heavy frame having a wall, said apertured portion beingattached at its peripheral edge to said wall of said frame, each of theapertures in said barrier being aligned with particular areas of saidmosaic screen; said mounting for said barrier in said tube includingmeans for maintaining said alignment during tube operation, saidlast-named means comprising: a plurality of temperature compensatingmounting members spaced about said wall of said frame, each comprising abimetallic baseplate formed from contiguous materials having differentthermal coefficients of expansion and being formed to have a protrudingextending loop extending therefrom, said loop being responsive totemperature changes within said tube and being formed between first andsecond ends of said baseplate; means for attaching a first end of eachof said baseplates to said wall of said frame; an opening formed in saidwall of said frame to receive said loop; cooperating baseplate locatingmeans formed on said first end of said baseplate and said wall toachieve substantially central location of said loop within said openingwhereby its nonbinding action is insured; said cooperating baseplatelocating means comprising a plurality of projections extending from theplane of said wall and a like number of openings in said baseplate, saidopenings being configured as said projections and providing a snug fitof said prOjections therein; a like plurality of spaced studs projectinginternally of said tube and attached to said envelope; and a likeplurality of leaf springs each having one end attached to one of saidstuds and the other end affixed to one of said second ends of one ofsaid baseplates.
 2. The invention of claim 1 wherein said projectionsare two in number.
 3. The invention of claim 1 wherein said projectionsare cylindrical.